P. Gyftou, M. Stroumbouli, E.A. Pavlatou, N. Spyrellis
Transactions of the Institute of Metal Finishing (2002), 80 (3), 88-91
Nickel matrix composite coatings containing micron- and nano-sized SiC particles were prepared in order to study the interdependence of the SiC particles embedding and the deposits 'mechanical behaviour. SiC particles of two different sizes, namely 1μm and 20nm, were codeposited with nickel from Watts solutions under pulse current conditions. It has been observed that the embedding of SiC particles in the nickel matrix and the pulse current application result in deposits with more uniform particle distribution and better surface morphology than those obtained under direct current conditions. The study of the composite deposits revealed that the microhardness is not only increased by the presence and the reduced size of the particles, but also influenced by the current conditions, i.e. duty cycle and pulse frequency. Moreover, microhardness of the deposits can be further ameliorated by specific thermal treatment.